A Seoul court on Friday sentenced a medical school student to 26 years in prison on charges of murdering his girlfriend for allegedly breaking up with him.

The 25-year-old, surnamed Choi, who attended a medical school in Seoul, was indicted with physical detention for stabbing his girlfriend to death on the rooftop of a building in southern Seoul on May 6.

The Seoul Central District Court handed down the sentence for Choi, saying he had "brutally murdered" the victim, who was blindsided by the defendant's criminal plan.

"It seems certain (the defendant) had an intention to kill, given he prepared a knife in advance and even bought duct tape before stabbing the victim numerous times," the court said, noting the method of the crime is "cruel" and "highly reprehensible."

Investigations found Choi had reportedly registered for marriage with his then girlfriend without telling their parents, but upon finding the news, the victim's parents later filed a nullity suit for the marriage.

Choi's side claimed he committed the crime in a state of mental disability, but psychiatric evaluation results proved otherwise. (Yonhap)